Key Largo
Florida, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Key Largo, FL

A clear seascape and cloudy evening sky in Key Largo, Florida
A clear seascape and cloudy evening sky in Key Largo, Florida
  • Average high temperature in September: 90°F

Warmest months (with the highest average high temperature) are July, August and September (90°F).
The month with the lowest average high temperature is January (75°F).

  • Average low temperature in September: 73°F

Months with the highest average low temperature are July, August and September (73°F).
Coldest months (with the lowest average low temperature) are January and February (57°F).

  • Average rainfall in September: 8.4"

The wettest month (with the highest rainfall) is June (10").
The driest month (with the lowest rainfall) is December (1.4").

  • Average rainfall days in September: 17 days

Months with the highest number of rainy days are August and September (17 days).
The month with the lowest number of rainy days is April (5 days).

  • Average sea temperature in September: 85.6°F

The best month for swimming (with the highest average sea temperature) is August (86.8°F).
The coldest month (with the lowest average sea temperature) is February (72.6°F).

  • Average daylight in September: 12h

Months with the longest days are June and July (Average daylight: 14h).
Months with shortest days are January, February, November and December (Average daylight: 11h).

  • Average sunshine in September: 9h

Months with most sunshine are April, May, June and July (Average sunshine: 10h).
Months with least sunshine are January, November and December (Average sunshine: 7).

  • Average UV index in September: 10

Months with the highest UV index are April, May, June, July and August (UV index 11).
The month with the lowest UV index is December (UV index 5).